Access is denied. Check that the Default Content Access Account has access to this content, or add a crawl rule to crawl this content. Event Id:2436

If you are getting the below error in event log in your SharePoint server 2007

Then follow the below solution steps

Method 1: Disable the loopback check
1. Click Start, click Run, type regedit, and then click OK.
2. In Registry Editor, locate and then click the following registry key:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Lsa
3. Right-click Lsa, point to New, and then click DWORD Value.
4. Type DisableLoopbackCheck, and then press ENTER.
5. Right-click DisableLoopbackCheck, and then click Modify.
6. In the Value data box, type 1, and then click OK.
7. Quit Registry Editor, and then restart your computer.
Method 2:- After I restarted the server I went to the Sharepoint Admin site and started a full crawl. Some seconds later I went to the crawl log and found a warning this time with the following entry: Content for this URL is excluded by the server because a no-index attribute.
So "Reset All Crawled Content" and tried the full crawl again.